Multi-omics landscape and molecular basis of radiation tolerance in a tardigrade.

Tardigrades are captivating organisms known for their resilience in extreme environments, including ultra-high-dose radiation, but the underlying mechanisms of this resilience remain largely unknown. Using genome, transcriptome, and proteome analysis of , we explored the molecular basis contributing to radiotolerance in this organism. A putatively horizontally transferred gene, DOPA dioxygenase 1 (), responds to radiation and confers radiotolerance by synthesizing betalains-a type of plant pigment with free radical-scavenging properties.